Wing of aeroplanes and the like aircraft



Jan. 5, 1932. F. SIGRIST 1,839,349

WING OF AEROPLANES AND THE LIKE AIRCRAFT Filed May 27, 1929 2 Sheets-Sheet 1 \i N A to ney Jan. 5, 1932. F. SIGRIST WING 0F AEROPLANES AND THE L'IKE Atacama 2 Sheets-Sheet 2 Filed May 27, 1929 INVENTOR;

10 stalling, while the outer wing is still liftthe said tips or outer portions may be greater 60 Patented Jan. 5, 1932 r 1,839,349

FREDERICK SIGRIST', F OXSHOTT, ENGLAND WING 0F AEROIPLANES AND THE LIKE AIRCRAFT Application filed May 27, 1929, Serial No. 366,208, and in Great Britain June 5, 1928.

This invention relates to the wings of aerO or Zones are of proportionally thickerv wing planes and like aircraft and has for its prisection than the said inner portions. mary object to obviate stalling and also t0 The proportionally greater thickness of improve the stability and control of such wing section may be obtained in two ways.

craft. Thus the distance from the front or leading When an aeroplane is flying in a circle, the edge to the rear or trailing edge (that is the inner wing is at a greater angle to the relative chord) of the tips or outer portions may be air than the outer wing, and this may result the same or similar to that of the inner p01- in the inner wingor the tip of the inner wing tion of the wing, and the actual thickness of ing. In other words the inner wing or the tip than the actual thickness of the inner portion.

of the inner wing may have passed the criti- Orythe actual thickness of the said tips or cal angle while the outer wing is still below outer portions might be the same as that of the critical angle; thus causing the machine the inner portion, and the proportionally 15 to get into a spin. greater thickness obtained by making the The object of the present invention is to' chord of the said tips less than the chord of provide a construction for the wings of aerothe inneripor'tion. 1 7 planes whereby the wings themselves, as In order to make the invention clear it will structures, and apart from any movable connow be described with reference to the actrolling means, shall possess inherent capaccompanying drawings wherein,- ity for obviating or reducing the liability to Figure 1 is a front view of a biplane in get into a spin as aforesaid when flying in which the upper wing is provided with wing a circle. 1 tips of thick section.

- It is well known that a wing of thick Figure 2 is a plan of such machine.

section will give a higher lift co-efiicient than Figure 3 is an end view of the wing showone of thin section and also that thesta1ling the relative position of the thin and ing angle of thick sections is greater than 'thick sections of the wings; and on a larger that of thin sections. Thus in the case of scale. the thin wing section known as R. A. F. 28 The upper wings of the biplane shown in 39 the maximum absolute lift co-eflicient is 0.47 Figures 1 and 2 are provided with tips of and at larger Jingles the lift co-efficient falls thickened section, The datum line la (Figaway rapidly, whereas in such a thick wing ure 3) for the thickened wing section of the section as that known as Go'ettingen 426 the Wing tip 1 in this particular example is set absolute lift CO-GfliCiBIit at 12 iS about 0.675 at a, negative angle of incidence with the 35 and this lift co-eifi e remalns p a y datum line 2a of the normal wing section of constant from 12 to 21. With other thm the central portions 2 of the wing. The chord g Sectlon? 11ft e s Q? 99 b: of the wing tips 1 is slightly greater than that l y Q Q Hefnce Wmg i film of the central portion 2 so as to permit the Section 15 Provlded Wlth tlp of two sections to be faired sweetly into each 4 tion t tip will t Stall before the central other without reverse surfaces, while the portlons of the Wmg even though thelioirmgr trailin edges 3 of both sections are in line. may be at greater angleto th? relablve an In aTnodification the actu l thickness of the El:t 27 g i gfi diaf g iy zg wing may be maintained 2011mm and the g c proportionally thick section may be 010-. 9

" the wlng.

The present invention therefore comprises tamed y makmg 1 Wmgs o 1655 actual an aeroplane or like aircraft wherein the tips, Wldth at the P $13311 P p y tar1361"ed outer portions or zones have a later stalling 111 p qflm he thlck sectlon merges angle than the inner portions, characterized gradually into the thin section, and such 1 by the fact that the said tips, outer portions tips may be Washed out to a negative angle or stepped out as a Whole to the same negative angle.

I claim 1. Aeroplanes or like aircraft having Wings of the same actual thickness of section throughout the span and outer portions of smaller dimensions from leading edge to trailing edge as compared With the inner portion to provide outer portions of proportionally thicker section than that of the section of the inner portion, substantially as described.

2. Aeroplanes or like aircraft having Wings of the same actual thickness of section throughout the span and outer portions of smaller dimensions from leading edge to trailing edge as compared With the inner portion to provide outer portions of proportionally thicker section than that of the section of the inner portion, the said outer portions being tapered in plan whereby the proportional thickness of section increases gradually towards the Wing tips, substantially as described.

3. Aeroplanes or like aircraft having Wings of permanent Wing section and wherein the outer portions, integral with the inner portion, are of proportionally thicker ing section than the Wing section of the inner portion, substantially as described.

4. Aeroplanes or like aircraft having Wings of permanent Wing section and wherein the outer portions, integral With the inner portion, are of greater actual thickness of Wing section than the Wing section of the inner portion, substantially as described.

FREDERICK SIGRIST. 

